Pilot pressure control mechanism



March 3, 1936. l.. J. GR1FFEY PILOT PRESSURE CONTROL MECHAISM Filed Oct. l1, 1954 2 Sheets-Sheet 1' llawlllllayfiyll/J.

-March 3, 1936. L, ,1 GRlFFEY 2,032,611

PILOT PRESSURE CONTROL MECHANISM Filed oct. 11, 1954 2 sheets-sheet 2` Patented Mar. 3, 1936 UNITED STAT-Es PATENT OFFICE Leon J. Griffey, Tulsa, 0kla.,assignor vto Hanlon-Waters, Inc., Tulsa, Okla.

Application October 1.1, 1934, Serial No. 747,992

19 Claims.

My invention consists in new and useful Vimprovements in a pilot pressure control device which is designed to give positive pressure control at any pressure setting with a minimum 5 .consumption of operating medium and a maximum exibility as to sensitivity of control and direction of action.

It is an object of my invention to provide a structure of this type which is free from the iusual tubing connections and small orifices which tend to become clogged with dirty operating medium or pipe scale.

Another object of my invention is to provide a convenient external hand adjustment for variation of the controlled pressure within the range of the controlling tube system.

A still further object of my invention is to provide a combined strainer and pressure regulator for controlling the pressure of the operat- 20 ing medium admitted to the motor valve diaphragm.

With the. above and other objects in view which will appear as the description proceeds, my invention consists in the novel features herein 2.3 -set forth, illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

Referring to the drawings in which numerals of like character designate similar parts 3,) throughout the several views,

Fig. 1 is a front elevation of my improved pilot pressure control device with the cover removed and showing the strainer and pressure regulator in section.

Fig. 2 is a transverse sectional View'taken on line 2-2 of Fig. 1.

Fig. 3 is a front elevation showing the assembly of the pilot pressure control in connection with a motor valve and vpipe line.

Fig. 4 is a detail section showing the pilot valve inset.

Fig. 5 is a View of the Bourdon tube and connecting links arranged for reverse action, and

Fig. 6 is a sectional view taken on line 6--6 of Fig. l, showing the double Bourdon tube arrangement.

In the drawings, I represents a housing having rear wall 2 and side walls 3 which merge at their upper extremities in a top wall 4, said housing being constructed of any suitable material and in any convenient shape. 5 represents a base member which supports the housing I and forms the bottom thereof, said base member consistinglof a 'horizontal casting drilled as 55,,at 6 to lformv a vertical opening which extends entirely `through the same and is adapted to receive a cylindrical valve inset 'I. The casting is also drilled longitudinally as at 8 and 9 to form passageways leading from opposite endsof the. casting to the vertical aperture 6, said passageways being independent of one another and preferably arranged in vertically spaced planes as shown in Fig. 1.

The valve inset 1 is provided with a. vertical bore I0 which extends entirely through theI same` and two transverse ports `I I and AI2 which extend from opposite sides of the periphery oi said inset and terminate at their inner extremities in c ommunication with said vertical bore. vImmediately adjacent the inner terminus of the transverse port I2, Vthe valve inset l is milled tov forma" horizontal slot I3a which extends toward the axis of the inset to a, depth slightly beyond the radial boundary of the vertical bore I0.

I3 Vrepresents a pilot valve head carried by vertically extending stem I4 which is slidaloly mounted in the bore I0 and projects upwardly beyond the Ytop of the valve inset 1, said pro'- jectingv end being threaded to engage complementary threads in a` gear I5 hereinafter re- ,l

ferred to more Yin detail. The valve stem I4 is reduced from a point adjacent the. Vport IIv to the upper end of the valve head I3 to permit the passage of fluid from port II through the bore I D -to port I2, and the valve headis preferably of a length slightly less than the vertical dimensions of the-milled slot I'3a. Thus the vertical vmovement of the valve stem in `either direction will cause the valve head I3 to move correspondingly in the slot I3a and throttle Aor completely close the respective portions of the bore I0. The slight upward Amovement of the valve member I3 throttles the bore I0 and cutsuoff communication between passageways 8 and 9 and establishes an increasing communication between passageway 9 and the lower extremity of bore `Ill kthrough port I2, whereby said passageway 9 is open to atmosphere. On the other hand, the slight downward movement of the `valve member I3 throttles or closes the atmospheric l relief port formed by the ,lower end of the ybore I0 and establishes an increasing communication between passageways 8 and 9.

The outer end of passageway 8 is internally threaded to receive a connection VI'I through which a suitable operating medium enters the passageway. The outer end of the passageway 9 is preferably threaded to receive a `plug I8, and at a point intermediate the ends of ,said passage- Way, the casting 5 is drilled vertically to kform i by means of a pipe 21 as and for the purpose Vscrew-threaded engagement with the upper end an opening I9 which communicates with the passageway 9 and is threaded to receive a connecting pipe 28 which leads to the diaphragm of the motor valve hereinafter referred to. The passageways 8 and 9 are arranged in communication with suitable pressure gauges 2| and 22, respectively, so as to indicate the existing pressures at these points.

Integral with the rear portion of the casting 5 adjacent the valve inset 1, IA provide a Bourdon tube support 23 which is vertically drilled as at 24 to receive the tubular shank 26 of a Bourdon tube element 29. This shank 26 is preferably provided adjacent its upper end with an enlargement 30 which serves as an abutment for the upper surface of the support 23, said enlargement being squared as shown in Fig. 1 to facilitate the application of a suitable tool during the assembly of the device. The lower end of the shank 26 is threaded to receive a lock nut 25 which embraces the undersurface of the casting 5 to retain the shank 26 and the Bourdon tube element 29 in position. The shank 26 projects downwardly beyond the lock nut 25, and by means of a suitable elbow, is connected to the controlled pressure line hereinafter set forth.

The Bourdon tube element preferably comprises a pair of Bourdon tubes 29 carried by a common base 28 which in turn is supported by of the shank 26, said Bourdon tubes being in communication with the controlled pressure line through the opening in the shank 26 and pipe 21.

'Ihe free ends of the Bourdon tubes 29 are preferably joined transversely and carry a projecting lug 3| to which is pivotally secured a lever 32, the other end of which is pivoted to a second lever 33. The lever 33 is provided with a longitudinally extending slot 34 adapted to receive a set screw 35,

4whereby said lever may be adjustably connected in fixed relation to one end of a rocker arm 36, the. latter being apertured and threaded to receive the threaded end of the set screw 35. The

rocker arm 36 is pivotally supported in a recess in the Bourdon tube base 28 as at 31 (Fig. 6) with its free end 38 normally abutting the top face of the valve gear I5.

[The free end of a slack spring 39 secured at its `opposite end to the casting 5 by means of a screw 140, extends through a transverse opening in the valvestem I4 and normallyY tends to force the valve upwardly with the gear I5 engaging the free end 38 of the rocker arm 36. It will thus be seen `that the movable member of the pilot valve floats vbetween the pressure force of the spring 39 normally urging the valve upwardly, and the action of the Bourdon tube assembly forcing the same downwardly in response to an increase in pressure in the main line 1I.

" LIt' isdesirable to vary the normal position of the valve member I3 with respect to the ports I I and I2 in the valve inset 1 from time td time, as Well ,as its relationship to and extent of movement by the Bourdon tubes, and for this purpose I vprovide an adjusting stem 4I which extends ver- 75. raise or lowerthe position of the valve in the vertical bore Il), or adjust the position of said gear I5 with respect to the free end 38 of the rocker arm 36.

The stem 4I is retained in place by means of a pointer clip 44 secured to the top wall 4 of the housing by suitable bolts 45, the free end of the pointer clip 44 serving to indicate the extent of rotation of the adjusting knob 42 which latter element may, if desired, be provided with calibrations or other indicia.

46 represents a combined strainer and pressure regulator adapted to be inserted in the operating fluid line for the purpose of preventing any dirt orpipe scale from entering the pilot valve mechanism and also for controlling the pressure admitted to theA diaphragm of the motor valve. This device comprises a strainer chamber 41 adapted to be filled with steel or rock wool or any other suitable ltering media, the lower-end of said chamber being closed by a threaded plug 48 by means of which the chamber may be cleaned from time andthe iiltering media replaced. An inlet boss 49 is provided in one of the side walls of the chamber 41 adjacent the lower end thereof,

which boss is threaded to receive the operating uid line 5D.

The upper end of the chamber 41 terminates in a valve housing 5I vertically drilled as at 52 to receive a conventional tire inner tube valve 53 having an upwardly extending stem 54 and being normally forced towards closed position by the upward pressure of a coil spring 55. Above the valve housing 5I is a diaphragm chamber 56 closed at its upper extremity by a flexible diaphragm 51, the latter being retained in place by the lower annular edge of a spring housing 58 screws 59 being provided for securing said spring housing in position. A coil spring 60 in the nousing 58 engages the upper face of the diaphragmv 51 at one end and a hollowadjusting screw 6I at its other end, said adjusting screw being threaded.

to engage complementary threads in the spring housing 58, and either knurled or squared at its upper end to facilitate adjustment thereof. Preferably a spring adapter 62 is provided on the upper face of the diaphragm to retain the adjacent end of the spring 68 in place, said adapter comprising a bolt which extends downwardly through the diaphragm and receives a nut 63 which lies on the underside of the diaphragm 51 and serves as an abutment for the valve stem 54. In operation, the spring 66 is ladjusted so as to cause the g diaphragm 51 and in turn the nut 63 to pushl downwardly on the valve stem 54, thus retaining the valve 53 in open position to permit the passage of operating uid through the strainer and valve and into the passageway 8 of the pilot valve, the latter being connected by means of pipe I1 to a threaded boss 64 in the adjacent wall of the diaphragm chamber 56.

A cover or closure 65 is adapted to t over the front face of the pilot valve housing I and is retained in place by any suitable means such as a screw 66 which extends through the cover and engages threads in the end of a horizontal port 61 mounted on the rear wall 2 of the housing.

The apparatus just described may be mounted either directly on a motor valve or it'may be installed on an instrument board, Fig. 3 of the drawings illustrating the former installation. In this connection, it will be noted that where it is not desired to mount the pilot valve assembly directly on the diaphragm of a motor valve, the

connection to the motor valve may be made to plug I8. In this event, plug I8 is used to close the opening I9 in the bottom side of the casting 5.

Referring to Fig. 3, it will be seen that the pipe 29 leading from passageway 9 in the pilot valve base or casting is connected at its lower end to a diaphragm chamber 68 which houses the diaphragm for controlling the operation of the mo-tor valve 69 through the medium of the valve stem 10. The motor valve 69 may be of any conventional type opening on the upward movement of the stem I0 and closing on the downward movement thereof, or vioeversa, said valve being installed in the line 'II which conducts the fluid to be controlled. The pipe 2'I leading from the shank 26 and Bourdon tubes 29 is provided with an extension 'I2 which is connected into the line II either on the upstream or downstream side of the valve 69 according to the nature of the installation, Fig. 3 showing this connection made to the downstream side of said pipe line as at 13.

Any suitable operating medium may be errrployed for operating the diaphragm 68 of the motor valve. It is preferable, however, to employ air or gas fed froml an auxiliary'source at a pressure suflicient to operate the motor valve. In the event that operating medium is supplied in'aolean stream and at a constant pressure no greater than that required to operate the motor valve, it is unnecessary to employ the strainer andl pressure unit 46, the line 50 being connected directly to the inlet of the passageway 8.

However, if the source of operating medium is not such as to afford a constant pressure and a clean stream of fluid, it is essential to the proper operation of the pilot pressure control to interpose the strainer and pressure regulator 46 in the operating fluid line as shown in Fig. 3. For example, if the fluid from the upstream side of the line 'II were used as an operating medium for the motor valve, by `connecting pipe 50 into the line II anterior to the valve 69, it would be necessary to install the combination strainer and pressure regulator L16. Naturally, the pressure of the fluid in the line 'II fluctuates, and without this regulator, the pressure. applied to the diaphragm chamber 98 might become greater than the diaphragm could stand. Furthermore, this regulator eliminates variations in diaphragm pressure upon slight variations of the inlet pressure.

Having thus described the construction and assembly of my improved pilot pressure control device as applied to a diaphragm operated motor valve, its operation is as follows:

Assuming that the motor valve 69 is of the type which closes on the upward movement of the stem 'I0 under the pressure of the conventional valve spring (not shown), and that the.

toggle lever arrangement connected to the free ends of the Bourdon tubes 29 is as shown in Fig. l. The pilot valve I3, by means of the adjusting stem 4I and knob 42, is adjusted to permit a normal now of operating medium from passageway 8 through ports II and I2 to passageway 9, and in turn through connection 20, to the diaphragm chamber 68 of the motor valve 69, thus retaining the latter in open position by the downward pressure of the diaphragm on the stem 1I). The diaphragm spring 60 in the strainer-regulator 46 is also adjusted b-y the screw 6I to permit a constant pressure on the operating fluid line.

Now, on an increase in pressure on the downstream side of line 'II over and abo-ve that for which the apparatus is set, said pressure is transmitted vthrough lines 12 21 and shank 26 to the Bourdon tubes 29 which causes the latter to expand. 'I'his in turn causes the levers 32 and V33 to rock the rocker arm 36 in a clockwise direction, thus elevating the free end 38 thereof and permitting the valve I3 to be forced upwardly b-y the slack spring 39. The port I2 in the valve inset 'I is now open to atmosphere through the lower extremity of the bore I0, thus permitting the escape of pressure from the motor valve diaphragm chamber t9 through connection 29, passageway 9, port I2 and bore I9. This permits the spring pressure on the underside of thev moto-r valve diaphragm to close the valve 69 until the pressure on the downstream side of the line 'II has dropped to the desired extent.

Upon the drop in pressure in line "II, the Bourdon tubes 29 contract and through levers 32 and 33, rock the rocker arm 36 in counterclockwise direction to return the Valve I3 to its former position, shutting orf or throttling the escape to atmosphere and again placing passageways 8 and 9 in communication to establish a pressure in the diaphragm chamber 68 and open the valve 69.

During the operation of this device, should the pressure on the operating lluid line 59 rise over and above the amount the motor valve diaphragm can safely stand, regulator diaphragm 51 will be forced upwardly out of contact with the valve stem Eil, thus permitting the valve .53 to close until a proper pressure -condition has been established. This operation is repeated so long as the pressure remains irregular on the line 59.

The toggle lever arrangement connected to the Bourbon tubes is capable of reversibility and is also adjustable for extent of movement. As shown in Fig. 5, these levers 32 and 33 are re.- versed so that upon the expansion of the Bourdon tubes 29, the levers will rock the rocker arm 36 f the slotted lever 33 is as shown in Fig. 5, an increase of controlled pressure will tend to increase the motor valve pressure, and by arranging this leverage as shown in Fig. 1, an increase of controlled pressure will tend to. decrease the motor valve diaphragm pressure.

Increasing the leverage of the slotted lever 33 by means of the adjusting screw 33, will decrease the pilot valve travel for a given change in controlled pressure. As the pilot valve travel is reduced, the motor valve diaphragm pressure response is throttled. Decreasing the leverage of the slotted lever 33 on the rocker arm increases the pilot valve travel for a given change in controlled pressure. As the pilot valve travel is increased, the motor valve diaphragm pressure response is increased. Thus by adjustment of this leverage for the correct speed of action, exact pressure control can be obtained on any pressure controlled installation,

It will thus be seen that I have provided a highly practical pilot pressure control mechanism which is easily adaptable to various different types of installations for controlling either pressure or Vacuum and one which is reversibleand readily adjustable both as to speed and degree of action.

` From theV foregoing it is believed that the construction and advantages of my invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set forth in the following claims.

What I claim and desire to secure by Letters Patent is:-

l. A pilot pressure control device comprising a conduit for conducting a motor valve operating fluid, a pilot valve interposed in said conduit, a Bourdon tube responsive to the pressure to be controlled, means normally tending to force said, pilot valve in one direction, a rocker arm for forcing said pilot valve in the opposite direction, and Variable means cooperating with said Bourdon tube for operating said rocker arm.

2. The combination with a main conduit and a motor valve therein, a pressure control mechanism comprising an auxiliary conduit for conducting an operating iiuid to the actuating member of said motor valve, a valve inset interposed in said auxiliary conduit, a movable valve member in said inset for controlling the flow of operating iluid to said motor valve and the escape of said operating fluid therefrom, means normally tending to force said valve member in one direction, a rocker arm for forcing said valve member in the opposite direction, a control device responsive to the pressure in said main conduit and operatively associated with said rocker arm, means for adjusting the position of said valve member with respect to said control device, and separate means operatively connected with said control deviceV for regulating the speed of action of said valve member.

V3. A pilot pressure control device including a casing, a base member in said casing, a passageway in said base member for conducting a motor valve operating fluid, a pilot valve interposed in said conduit, a Bourdon tube support carried by -said base member, a Bourdon tube thereon, the

latter being responsive to the pressure to Ybe controlled, means normally tending to force said pilot valve in one direction, and means controlled by the movement of said Bourdon tube for forcing said pilot valve in the opposite direction,

4. A pilot pressure control device including a casing, a base member in said casing, a passageway in said base member for conducting a motor valve operating fluid, a'pilot valve interposed in said conduit, a Bourdon tube support carried by said base member, a Bourdon tube thereon, the latter being responsive to the pressure to be controlled, means normally tending to force said pilot valve in one direction, means controlled by the movement of said Bourdon tube for forcing said pilot valve in the opposite direction, and means for adjusting the position of the movable member of said pilot valve with respect to said last named means.

5. A pilot pressure control device including a casing, a base member in said casing, a passage- Way in said base member for conducting a motor valve operating fluid, a pilot Valve interposed in saidV conduit, a Bourdon tube support carried by said base member, a Bourdon tube thereon, the

Vlatter being responsive to the pressure to be con- 4forcing said pilot valve in the opposite direction.

6. A pilot pressure control device comprisinga base member, a conduit in said base member for.

conducting a motor valve operating uid, a pilot valve assembly interposed in said conduit, a Bourdon tube support carried by said base member,- a Bourdon tube thereon, the latter being responsive to the pressure to be controlled, a rocker arm pivotally mounted on said Bourdon tube support with its free end in abutting relation to the movable member of said pilot valve assembly, the other end of said rocker arm being operatively connected to the free end of said Bourdon tube, and means normally tending to force the movable member of said pilot valve assembly toward the free end of said rocker arm.

7. A device as claimed in claim 6 wherein said Bourdon tube support carries a pair of parallel Bourdon tubes arranged in communication with one another.

8. A pilot pressure control device comprising a base member, a conduit in said base member for conducting a motor valve operating uid, a pilotvalve assembly interposed in said conduit, a Bourdon tube support carried by. said base member, a Bourdon tube thereon, the latter being responsive to the pressure to be controlled, a rocker arm pivotally mounted on said Bourdon tube support end of said Bourdon tube, and means normally l tending to force the movable member of said pilot valve assembly toward the free end of said rocker arm.

9. A pilot pressure control device as claimed in claim 8 wherein said levers are reversible'iorv causing the reverse action of said pilot valve.

10. A pilot pressure control device comprising a housing, a base member in said housing, a conp duit in said base member connected at one point tube thereon, the latter being responsive to thepressure to be controlled, a rocker arm pivotally mounted on said Bourdon tube support with its free end in abutting relation to the movable member of said pilot valve assembly, the other end of said rocker arm being operatively connected to the free end of said Bourdon tube, and

-means normally tending to force the movable member of said pilot valve assembly toward the free end of said rocker arm.

11. A pilot pressure control device as claimed in claim 10 wherein said pilot valve assemblycomprises a stationary inset interposed in said conduit, a, passageway extending through said inset to establish communication through said conduit, and a valve member in said inset adapted to control the passage of operating fluid` through said passageway.

12. The combination with a conduit and a motor valve therein, of a pressure control mechanism comprising a pilot valve for controlling the pressure on the operating member of saidv motor valve, a Bourdon tube support, a Bourdon tube carried thereby, the latter being responsive to the pressure at a predetermined point in said conduit, a rocker arm pivotally mounted on said Bourdon tube support With its free end in abutting relation to the movable member of said pilot valve, the other end of said rocker arm being operatively connected to the free end of said Bourdon tube, and means normally tending to force the movable member of said pilot valve toward the free end of said rocker arm.

13. In a valve mechanism, a stationary valve body, a movable valve member, a Bourdon tube support, a Bourdon tube carried thereby, a rocker arm on said support arranged With one end in abutting relation to the movable member of said valve, a lever fixed to the other end of said rocker arm, a second lever connecting the latter tothe free end of said Bourdon tube, and means normally tending to force the movable member oi said valve to the free end of said rocker arm, the expansion of said Bourdon tube causing said rocker arm to move in a direction away from said movable member.

i4. In a valve mechanism, a stationary valve body, a movable valve member, a Bourdon tube support, a Bourdon tube carried thereby, a rocker arm on said support arranged with one end in abutting relation to the movable member of said Valve, a lever xed to the other end of said rocker arm, a second lever connecting the latter to the free end of said Bourdon. tube, and means normally tending to force the movable member of said valve toward the free end o said rocker arm. the expansion of said Bourdon tube causing said rocker arm to move in a direction toward said movable member.

l5. In a valve mechanism, a stationary valve body, a movable valve member, a Bourdon tube support, a Bourdon tube carried thereby, a rocker arm on said support arranged With one end in operative engagement With the movable member of lsaid valve, a lever xed to the other end of said rocker arm, a second lever connecting the latter to the free end of said Bourdon tube, and means normally tending to force the movable member of said valve toward the free end of said rocker arm, the expansion of said Bourdon tube causing said rocker arm to move in a direction away from said movable member.

16. A device as claimed in claim 15 wherein the upper end of the movable member of said valve is threaded to engage complementary threads in a gear member, the latter forming the abutment for said rocker arm, a second gear member meshing with said first named gear, and means for rotating said second gear to adjust the position of the movable member of said valve.

17. A pilot pressure control mechanism comprising a housing, a base member in said housing, a conduit in said base member for conducting a motor valve operating iluid, a pilot valve assembly interposed in said conduit comprising a stationary valve body, a movable valve member in said body adapted to control the iiow of iiuid through said conduit and the venting of fluid therefrom, a Bourdon tube support on said base member, a Bourdon tube carried thereby and arranged in communication with the pressure to be controlled, a rocker arm pivotally mounted on said support with one end in operative engagement with the movable member of said valve,

a lever xed to the other end of said rocker arm,.

a second lever connecting said first named lever to the free end of said Bourdon tube, a valve adjusting stem extending to the exterior of said housing, means actuated thereby for adjusting the relative position of said movable member with respect to the valve body member, and a spring member normally tending to force said movable member into engagement with said rocker arm.

18. The combination With a main conduit, a motor valve therein and an auxiliary conduit for supplying a pressure operating fluid to the actuating member of said motor valve, of a control mechanism for said actuating member comprising a floating pilot valve for regulating the flow of operating fluid to said actuating member and the release of said fluid from the latter, means normally tending to force said pilot valve in one direction, a Bourdon tube responsive to 5" the pressure in said main conduit, and a rocker arm intermediate the pilot valve and said Bourdon tube and operatively connected to the latter for forcing said pilot valve in the opposite direction.

19. The combination With a main conduit, a motor valve therein and an auxiliary conduit for supplying a pressure operating iiuid to the actuating member of said motor valve, of a control mechanism for said actuating member comprising a floating pilot valve for regulating the flow of operating uid to said actuating member and the release of said fluid from the latter, means normally tending to force said pilot valve in one direction, a valve control device responsive to the pressure in said main conduit, and a series of adjustable levers operatively associated with said control device for forcing said pilot valve in the opposite direction.

LEON J. GRIFFEY. 

